PROJECT SUMMARY/ABSTRACT (EXPERIMENTAL IRRADIATION) The Experimental Irradiation (EI) Shared Resource (SR) provides access to state-of-the-art equipment and expert consultation for University of Michigan Comprehensive Cancer Center (UMCCC) members undertaking radiation therapy studies in mouse models and cell lines. First established in 1991, this SR has been approved and funded continuously by the NCI CCSG since its inception. At the last CCSG renewal, the EI SR received a merit rating of ?Outstanding.? The services of this SR are critical to members interested in radiation biology and radiation therapy, as well as those for whom radiation serves as a research tool.